Roughly how many hours of SD recordings can I stor...

Question

Hi,
I was just wondering as to the capacity of my box.
I thought it was 160gb, or around 80 hours of standard recordings, but by my reckoning I've got about 90 hours on there and the purple bar in the top right is only about two-thirds of the way across.
Also, is there an exact way that I can see how much disk space I have?
I'd prefer to see an actual figure rather than just guess what the purple bar is.
Thanks.

Answer 1

BT state that the 160GB versions can hold ~80 hours of SD and the 500GB versions can hold ~300 hours of SD or ~125 hours of HD.
At first glance that doesn't seem to quite add up, but just for fun(?) let's assume that some of the hard-disk is used to store the file system, linux OS, BT Vision software and configuration data. Let's also assume that this area is always the same fixed size and BT are always using the same multiplier for SD recordings (big assumptions indeed  ).
We could then say,
SYS + (HDR x 125) = 500
SYS + (SDR x 300) = 500
SYS + (SDR x 80) = 160
which gives,
SYS = 36.3636
SDR = 1.5455
HDR = 3.7091
So going by BT's own figures roughly 36GB is already used by the system, each hour of SD recording uses roughly 1.5GB, and each hour of HD recording uses roughly 3.7GB.
This would mean a 320GB hard-disk would allow for the 36GB system data plus roughly 184 hours of SD recordings or 76 hours of HD recordings.